<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  
  <script>
    function sum(a){
      let sum=0
      for(let i=0;i<a.length;i++){
        if(a[i]%2===0){
         sum+=a[i]
        }
      }
      return sum
    }
 let arr=[1,8,6,7,5,9]
 console.log(sum(arr));

  </script>
</body>
</html>